Finding Static Equilibrium: Solving for Unknown Angles

6 replies · 2K views · last reply
Ping427
Messages
7
Reaction score
0
Can anyone help me with this question! I know to solve this problem, you have to set ΣF and ΣM =0, but what do you do with angle? (It's P.31 in the bottom)
 
Attachments
  • Textbook page showing Problem P4.30 with a bearing housing and a 85 lb arrow, and Problem P4.31 with a shaft diagram labeled A and B, a 1 kN force upward at A, a 1.4 kN force downward at the middle pulley, and spacings of 6 cm and 6 cm.
    image.jpg
    48.4 KB · Views: 481
  • Textbook page, rotated, showing Problem P4.32 with a diagram of a pot on a bracket with dimensions 65 mm, 70 mm and 150 mm and a 60 degree angle, and below it a parabolic solar reflector with supports labeled A and B.
    image.jpg
    53 KB · Views: 465
Hi Ping, welcome to PF :smile: !

Sure! To get started, extract a complete and concise problem statement from this moving stoy. That helps you sort out what's known/unknown and what's relevant/irrelevant. Then help us help you at the appropriate level by typing some equations relating the variables that occur.
What also heklps is a free body diagram showing the forces that act.
Then try to solve and type what you do. At the point where you get stuck we'll gladly help you further. Also see the guidelines.

PS my neck hurts from trying to read from bottom to top.
 
BvU said:
Hi Ping, welcome to PF :smile: !

Sure! To get started, extract a complete and concise problem statement from this moving stoy. That helps you sort out what's known/unknown and what's relevant/irrelevant. Then help us help you at the appropriate level by typing some equations relating the variables that occur.
What also heklps is a free body diagram showing the forces that act.
Then try to solve and type what you do. At the point where you get stuck we'll gladly help you further. Also see the guidelines.

PS my neck hurts from trying to read from bottom to top.
This is what I did, but it looks wrong to me
 
Attachments
  • Handwritten statics solution on lined paper for problem P4.30: beam with Support A and Support B, a 70 mm load W1 and a 65 mm link at 60 degrees carrying W2, with force and moment equations and computed values for By and Ay.
    image.jpg
    47.5 KB · Views: 466
Ping427 said:
Can anyone help me with this question! I know to solve this problem, you have to set ΣF and ΣM =0, but what do you do with angle? (It's P.31 in the bottom)
Why do you think you need to do anything with the angle? The location of the center of gravity for the music player is shown on the figure. :wink:

If you want to express the reactions Ay and By in correct SI force units of Newtons, you should change the masses of the music player and the docking station from grams to kg at the beginning.
 
SteamKing said:
Why do you think you need to do anything with the angle? The location of the center of gravity for the music player is shown on the figure. :wink:

If you want to express the reactions Ay and By in correct SI force units of Newtons, you should change the masses of the music player and the docking station from grams to kg at the beginning.
So they just place a angle there to trick me?
 
Ping427 said:
So they just place a angle there to trick me?
Sadly, yes.
 
SteamKing said:
Sadly, yes.
Thank you for telling me!:smile: